iterator for 2d vector

Question

How to create iterator/s for 2d vector (a vector of vectors)?

Answer 1

You can use range for statement to iterate all the elements in a two-dimensional vector.

vector< vector > vec;

And let's presume you have already push_back a lot of elements into vec;

for(auto& row:vec){
   for(auto& col:row){
      //do something using the element col
   }
}